There must be some intelligent way to use Oracle 9i XML capabilities here

Question

Hello all
I have to perform what is essentially a simplification of an XML interface. There is a company, OurProvider, who do lots of clever stuff with XML, and have tens of interfaces, XSDs etc and many ways to skin a cat. My company is using them as a backbone/provider but is embarking on a consolidation and simplification of the services they provide. We've boiled it down to 2 interfaces and 1 report.
Taking just one of the interfaces as an example:
OurClient <-- xml --> Us <-- xml --> OurProviderI have the XSDs for both sides of this.
When our client sends a file, I will transform it and add a unique transaction reference, then submit it to the provider
By way of return file, the provider sends us XML of what was done
Using the unique tx ref we submitted, we'll respond to the client
Later we might get a report in XML of activity the provider has engaged in on our behalf and some of that our client will want to know, so there is another feed that is "report" style rather than "request response" style
At the moment, I'm planning to receive the XML from the client, deserialize it in .net, insert it into a relational table (it's not a deeply nested or complex xml) having an oracle sequence provide the unique transaction reference. I'll then run a query to select the contents back into .net dataset constructed so that when I serialize it, it forms XML valid for the provider and then I can send it off.
On the return, I will deser the provider XML, look up the txn ref, look up the source record data from the client and append more info to it (sometimes jsut a result, but we return to them most of what they submit as confirmation), including THEIR ref
I'm just wondering if there is a more intelligent way of doing this? Maybe like having a table that has a column triggered to get an autonumber, and to be able to say to oracle "here's an xml document, store it into that table so that each node under the root becomes one row, then give me a document back after having applied this transform, and with the sequence number in the xml"
Example, the client presents:
<fruits>
  <fruit>apple</fruit>
  <fruit>pear</fruit>
</fruits>
The table could be:
id, xmltype
0, <fruit>apple</fruit>
1, <fruit>pear</fruit>
The provider wants:
<menu>
  <desserts>
    <dessert>
      <id>0</id>
      <name>apple</name>
    </dessert>
    <dessert>
      <id>1</id>
      <name>pear</name>
    </dessert>
  </desserts>
</menu>Any suggestions welcome!
Thanks
CJ
Edited by: charred on Aug 7, 2009 10:03 AM

Answer 1

I would suggets using XSLT. With XSLT you can apply a transformation to the original xmldocument. For your example it would look something like this:
DECLARE
newxml sys.xmltype;
sourcexml sys.xmltype;
xsltsrc sys.xmltype;
reslt VARCHAR2(4000);
BEGIN
newxml := xmltype('<fruits>
  <fruit>apple</fruit>
  <fruit>pear</fruit>
</fruits>
xsltsrc := xmltype.createxml('<?xml version="1.0" ?>
                             <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
                             <xsl:template match="/">
                                   <menu>
                                     <xsl:apply-templates/>
                                   </menu>
                             </xsl:template>
                             <xsl:template match="fruits">
                                   <desserts>
                                     <xsl:apply-templates/>
                                   </desserts>
                             </xsl:template>
                             <xsl:template match="fruit">
                                   <dessert>
                                       <xsl:choose>
                                        <xsl:when test="text() = ''apple''">
                                           <id>0</id>
                                         </xsl:when>
                                         <xsl:when test="text() = ''pear''">
                                           <id>1</id>
                                         </xsl:when>
                                         <xsl:otherwise>
                                          <id>-1</id>
                                         </xsl:otherwise>
                                       </xsl:choose>
                                     <name>
                                        <xsl:apply-templates/>
                                     </name>
                                   </dessert>
                             </xsl:template>
                             </xsl:stylesheet>');          
sourcexml := newxml.transform(xsltsrc);
reslt := sourcexml.getstringval(); -- print the result
dbms_output.put_line(substr(reslt, 1, 255));
END;